That Beaufort animation is pretty frightening. Highly-mobile ice gets "shaken" loose into a bunch of floes sitting in open water. Who needs melt ponds when you can just have interstitial open water sucking up all that insolation?

And the remaining ice in the Beaufort is supposedly some of the thicker ice in the Arctic right now. Doesn't reassure me about the CAB's prospects in the coming months.

And the surface melting images. The "melt pond extent" has increased again.

Stupid question - but what do the colors on the image mean? And how directly does that translate to melt pond extent

Jim, attached is the legend that is lost when I prepare the image in a standard format. Ice thickness is not reliable in this season due to melting. Melting obviously should be of use now.

As discussed previously, I presume "ice melt concentration" is the same as "melt pond concentration". I do not know how useful this data is, regard it as research.

The average should be decent once the melt pond concentration is high enough but there's a lot of scatter in the correlation between the actual melt pond concentration and the satellite measured brightness temperature index its correlated with so if you aren't averaging over a decent sample size the error bars are large, and if the average concentration is near 0 there's a significant high bias.

The surface melting situation. As expected from the area up-ticks in some regions, the extent in melt (as indicated by ADS/Jaxa map) is decreased.

I was interested in Neven's predictions of warm water entering the Bering Strait and finishing off the ice in Beaufort. There was even a time when there was continuous open water along the northern coast of Alaska and NW Territories. But your animation shows the ice has now closed up and for some time now I haven't seen much incursion of open water on the Arctic side of Bering Straight. What do you make of that?

The surface melting situation. As expected from the area up-ticks in some regions, the extent in melt (as indicated by ADS/Jaxa map) is decreased.

I was interested in Neven's predictions of warm water entering the Bering Strait and finishing off the ice in Beaufort. There was even a time when there was continuous open water along the northern coast of Alaska and NW Territories. But your animation shows the ice has now closed up and for some time now I haven't seen much incursion of open water on the Arctic side of Bering Straight. What do you make of that?

Welcome, Feeltheburn (what's with the Bernie Sanders pic? ). I didn't predict warm water to finish off the ice near the coasts of the Beaufort Sea. I expected just enough to wind to push it away, but the winds turned. Then I thought that maybe higher air temps and solar radiation would do the trick, but the wind picked up some more (check out my latest blog post on the ASIB).

So now I just wait and see what the Arctic will do with that ice and how soon things open up. Remember, it wasn't until the first week of July that the coast was entirely clear of ice on the Uni Bremen sea ice concentration map, in 2009 and 2011.

The animations shows ESS and Laptev. Melt and restoration are changing daily. The last few days melting is hitting the fast ice in Laptev hard. The pitch black ice in the last frame has less than 15% concentration.

Welcome, Feeltheburn (what's with the Bernie Sanders pic? ). I didn't predict warm water to finish off the ice near the coasts of the Beaufort Sea. I expected just enough to wind to push it away, but the winds turned. Then I thought that maybe higher air temps and solar radiation would do the trick, but the wind picked up some more (check out my latest blog post on the ASIB).

Neven, sorry if I misstated what you had said. As I indicated I have been a lurker and therefore probably lose some of the nuance and also probably form an incorrect impression.

I guess my picture and name are a double entendre? I nabbed the picture from the internet!

The century area drop is enough to just stay ahead of 2012. The lead in extent with its slower decline has now nearly evaporated.

Regional extent declined in Kara (-16k), Greenland Sea (-16k) and Beaufort (-12k). Extent in the CAB increased by +14k.Area lost -31k in the Greenland Sea, -22k in Hudson and -21k in the Beaufort. Smaller declines in ESS, Laptev and Kara (-17k, -13k and -13k).

Today's highlighted region is the Greenland Sea. The colorful composition in red and blue is a area with ice concentration hovering around the 15%.

Today's highlighted region is the Greenland Sea. The colorful composition in red and blue is a area with ice concentration hovering around the 15%.

I'd like to "unlurk" to thank Wipneus for all his fantastic images and graphs. And to point out that Iceland has not had sea ice along its shores in June for at least some centuries (except for the occasional large iceberg in late summer, calvings from the great Greenland glaciers).

In winter, drift ice from the far north occasionally settles in the fjords in the north-west, the last time this happened was in January 2007 (as far as I know).

The changes in sea ice around Iceland in Wipneus' image is perhaps a reminder that satellites are not perfect?

Today's highlighted region is the Greenland Sea. The colorful composition in red and blue is a area with ice concentration hovering around the 15%.

I'd like to "unlurk" to thank Wipneus for all his fantastic images and graphs. And to point out that Iceland has not had sea ice along its shores in June for at least some centuries (except for the occasional large iceberg in late summer, calvings from the great Greenland glaciers).

In winter, drift ice from the far north occasionally settles in the fjords in the north-west, the last time this happened was in January 2007 (as far as I know).

The changes in sea ice around Iceland in Wipneus' image is perhaps a reminder that satellites are not perfect?

The satellites are what they are. The ice around Iceland (and other coasts) is not counted (by my computation) in the area and extent figures as they are. A, what I call "coastal ice filter", gets rid of most of it.

Most of the extent drop are in Kara and Hudson (-23k and -21k), reliable decliners.Area, as always very volatile, went down especially strong in CAA (-51k), across the Arctic Laptev area increased by +33k. The CAB, Kara, Baffin, Hudson and Chukchi declined some -20k an average.

Today's regional delta map is from the CAA , parts of it seem to be baking in the summer.

As much as I appreciate the AMSR2 data you produce I'm finding the short time scale available frustrating. So I've just updated from your NSIDC concentration based data. I note that the massive errors in April have stopped. Is the source concentration data now from the uncalibrated F18 stream?

As much as I appreciate the AMSR2 data you produce I'm finding the short time scale available frustrating. So I've just updated from your NSIDC concentration based data. I note that the massive errors in April have stopped. Is the source concentration data now from the uncalibrated F18 stream?

Looking at the graph on page 1, 2012 extent seems lower than 2016, not higher. How do you get it as still being higher? Surely once the 10km footprint calculation separates from the 2.5km one, the 12.5km value has to be at least as high as the 10km one, not with the 2.5km one? .

Looking at the graph on page 1, 2012 extent seems lower than 2016, not higher. How do you get it as still being higher? Surely once the 10km footprint calculation separates from the 2.5km one, the 12.5km value has to be at least as high as the 10km one, not with the 2.5km one? .

Attached is a blow-up of the extent graph. The black line (2016) is still under the orange line (2012). I did fix a one-day off error in this graph (leap day problem) yesterday, so I am surprised you are still seeing it.

The Jaxa (10km) separates because of their change in algorithm from dry ice to wet ice. Starts 1 June and takes about 10 days.

I choose to show the 12.5 km SSMIS ASI calculation for 2012, because it has excellent agreement during 2013 and 2014 as well. The 3.125 km or 12.5 km do not seem to matter that much here.

As much as I appreciate the AMSR2 data you produce I'm finding the short time scale available frustrating. So I've just updated from your NSIDC concentration based data. I note that the massive errors in April have stopped. Is the source concentration data now from the uncalibrated F18 stream?

The numbers indicate a very slow day and 2012 taking the lead. However the image (attached) shows that there are problems, mostly on the Atlantic side. So I skip discussion of numbers and animations today, unless an interim update will arrive (did happen before).

The short answer is that the thickness is not reliable in the presence of melt ponds:

The product of sea ice thickness and the melt pond concentration which is shown in the VISHOP is calculated from AMSR-E and AMSR2 data by using a research algorithm1) developed by K. Tateyama (Kitami Institute of Technology) and others in the Arctic research projects utilizing the IARC-JAXA Information System (IJIS) and satellite imagery (1st - 4th generations). This product is an essentially experimental and research product. This product has the effectiveness in the relative dry freezing seasons such as autumn, winter and spring (September – May), but cannot provide the accurate sea ice thickness in melting wet season (June - August) because the sea ice surface is covered by melt ponds.

You can see that thickness is derived from the polarization ratio of the emissions in the 36GHz band. Thickness has a very nonlinear relation to the said ratio. That means slight deviations from the model have a big influence on the result. Think melt ponds, but also ice with large thickness variation will not give you a good estimate of the average thickness.

As they say in the link above:

This product is opened to the public for the usages of research and validation of algorithms.

Today's sea ice concentration seems to be OK. Since I still not trust yesterday's data, I would not pay too much attention to the one-day difference reported.What we can see is that the totla figures are now very close (just above) 2012. There is a couple of days of slow 2012 declines ahead, so 2016 may take the lead again.Temporary or not.

The state of surface melting. The total "melt pond extent" (from ADS/Jaxa AMSR2 data) did increase. From the animation we see that this did happen almost everywhere except in ESS and Laptev where the melting lessened. Also the intensity (melt pond concentration) intensified in many places, the same spot in the CAA that I noticed above is deep blue here.

The only region where extent drooped significantly is Greenland Sea (-25k).The area measures are more in a flux, declines in Hudson, Greenland Sea and CAB (-28k, -28k and -19k). The Laptev and ESS increased in area (+39k and +13k).

Since NSIDC and Jaxa data are missing, I attach the whole delta map. Notice the concentration drop over the Lincoln Sea and the (apparent) cold on the Asian side.

(no surface melting reported today, the ADS server seems to be in maintenance)